The present disclosure generally relates to semiconductor devices, and specifically relates to a device and method for protecting front-end-of-the-line (FEOL) elements and back-end-of-the-line (BEOL) elements.
FEOL elements are individual elements, e.g., transistors, diodes, resistors, which formed on the first portion of integrated circuit (IC) fabrication. BEOL elements are wiring elements which formed on the second portion of IC fabrication where the individual elements get interconnected with wiring on the IC wafer. More specifically, after the last FEOL process, there is a wafer with isolated elements (without any wires). In BEOL processes, contact pads, interconnect wires, vias and dielectric structures are formed to connect those isolated elements.
Complementary metal-oxide-semiconductor (CMOS) technology is the predominant fabrication technology for integrated circuit (IC). As technology advances, micro electromechanical system (MEMS) can be attached to a CMOS wafer to form a CMOS-MEMS device. Merely by way of example, the CMOS-MEMS device may include an accelerometer, a pressure sensor, an angular sensor, a microphone and others, and these micro devices include many advantages, such as low power consumption, short response time, and low drive voltage. However, while the size of the CMOS-MEMS device decreases, the FEOL elements and BEOL elements are apt to suffer from process damage, causing low yield in fabricating the CMOS-MEMS device.